Method and device for processing optical workpiece surfaces

• US 7,765,903 B2
• Filed: 08/02/2005
• Issued: 08/03/2010
• Est. Priority Date: 08/02/2004
• Status: Active Grant

• Current Assignee: Carl Zeiss Vision GMBH (Carl-Zeiss-Stiftung)
• Original Assignee: Carl Zeiss AG (Carl-Zeiss-Stiftung)
• Inventors: Michels, Georg, Schorcht, Ralf
• Primary Examiner(s): FRIDIE JR, WILLMON
• Application Number:
  US11/658,426
• Publication Number:
  US 20070247589A1
• Time in Patent Office: 1,827 Days
• Field of Search: 82/11.1, 82/15, 821/17, 821/18, 821/33, 821/37, 29/27.C, 29/28, 451/42
• US Class Current: 82/1.11
• CPC Class Codes: B24B 13/00 Machines or devices designed for grinding or polishing optical surfaces on lenses or surfaces of similar shape on other work; Accessories therefor edging optical work, e.g. lenses, prisms B24B9/14
• CPC Class Codes: B24B 13/023 for grinding several lenses simultaneously
• CPC Class Codes: Y10T 82/10 Process of turning
• CPC Class Codes: Y10T 82/25 Lathe

Abstract

The invention relates to a method for processing the surfaces of optical workpieces (3) such as optical or eye glass lenses carried out with the aid of a tool (5) and consisting in holding at least one workpiece (3) in a work piece receiving support (4) which is rotatable around the axis of a workpiece spindle (1′). The invention is characterized in that the workpiece (3) is received in the receiving support (4) in such a way that the axis of rotation (2) of the workpiece spindle is placed remotely from the axis (8) of at least one workpiece (3) and the axis (18) of the workpiece support is at least partially in a parallel position to the axis of rotation of the workpiece spindle.

Claims

1. A method for processing surfaces of optical workpieces having non-rotationally symmetrical and/or aspherical surfaces, such as lenses or spectacle glasses, by means of at least one tool which is fed by means of a tool feed unit for the processing of the non-rotationally symmetrical and/or aspherical surfaces, at least one optical workpiece being held in a workpiece fixture rotating about an axis of rotation of a workpiece spindle, the at least one optical workpiece being received by the workpiece fixture in such a way that the axis of rotation of the workpiece spindle runs at a distance from a workpiece axis of the at least one optical workpiece, and from a longitudinal axis of the workpiece fixture, the longitudinal axis of the workpiece fixture lying at least approximately parallel to the axis of rotation of the workpiece spindle, and the axis of rotation being coupled to the feed movement of the at least one tool.

2. The method as claimed in claim 1, wherein the axis of rotation of the workpiece spindle runs outside the at least one optical workpiece.

3. The method as claimed in claim 1, wherein in a processing of a curved surface of the optical workpiece, the optical workpiece is oriented such that, in the case of a different surface curvature, the path curve segments to be covered by the at least one tool, which place lower demands on a movement travel arising from a larger radius of the curved surface, run tangentially with respect to a cutting direction of the at least one tool, and in that surface curve segments which place high demands on a movement travel arising from a smaller radius of the curved surface run radially in a direction of advance of the at least one tool.

4. The method as claimed in claim 1, wherein at least two optical workpieces are mounted in each case in a workpiece fixture.

5. The method as claimed in claim 4, wherein said optical workpieces are mounted at least approximately in one plane.

6. The method as claimed in claim 4, wherein said at least two optical workpieces are processed by one and the same tool.

7. The method as claimed in claim 1, wherein said at least one optical workpiece is processed by at least two different tools.

8. The method as claimed in claim 1, wherein said tool used is a lathe chisel.

9. The method as claimed in claim 8, wherein at least one tool is provided as a preliminary turning tool and at least one tool as a precision turning tool.

10. The method as claimed in claim 9, wherein a polycrystalline diamond tool is used for the preliminary turning tool and a monocrystalline diamond tool is used for the precision turning tool.

11. The method as claimed in claim 1, wherein a simultaneous processing of a plurality of optical workpieces at least two tools takes place.

12. The method as claimed in claim 1, wherein a plurality of optical workpieces are arranged symmetrically and/or asymmetrically to the axis of rotation of the workpiece spindle.

13. The method as claimed in claim 1, wherein a plurality of optical workpieces are arranged one behind the other radially with respect to the axis of rotation of the workpiece spindle.

14. The method as claimed in one of claim 1, wherein a plurality of optical workpieces in one or in a plurality of annular forms are arranged on the workpiece spindle.

15. The method as claimed in claim 1, wherein a feed of the at least one tool together with the tool cutting edge takes place via a pivoting movement.

16. The method as claimed in claim 15, wherein for the pivoting movement, a pivot axis of the at least one tool lies at least approximately perpendicular to the axis of rotation of the workpiece spindle.

17. The method as claimed in claim 1, wherein a feed of the at least one tool takes place at least approximately parallel to the axis of rotation of the workpiece spindle.

18. The method as claimed in claim 1, wherein the workpiece axes can be set at an angle to the axis of rotation of the workpiece spindle.

19. The method as claimed in claim 1, wherein a movement travel of the at least one tool is interpolated in interspaces with respect to the next optical workpiece to be processed, outside the optical workpiece, with travel parameters for a continuously smoothed path of the at least one tool.

20. The method as claimed in claim 19, wherein the movement travel between two adjacent workpieces is less than 30 mm, preferably less than 10 mm.

21. The method as claimed in claim 1, wherein a tool feed unit with a stroke frequency of >

15 000 Hz, preferably of >

20 000 Hz, with a stroke of up to 35 mm is used.

22. The method as claimed in claim 1, wherein a radial advancing movement of the at least one tool with respect to the optical workpiece takes place via the workpiece spindle.

23. The method as claimed in claim 1, wherein after chip-removing processing, the at least one workpiece is polished or ground in the same tool fixture.

24. A processing device for surfaces of optical workpieces having non-rotationally symmetrical and/or aspherical surfaces, such as optical lenses or spectacle glasses, with at least one tool which is fed by a tool feed unit for processing the non-rotationally symmetrical and/or aspherical surfaces, with at least one workpiece fixture rotating about an axis of rotation of a workpiece spindle and on which the optical workpiece is received with a workpiece axis, the axis of rotation of the workpiece spindle lying at a distance from the workpiece axis and from a longitudinal axis of the workpiece fixture, the longitudinal axis of the at least one workpiece fixture lying at least approximately parallel to the axis of rotation of the workpiece spindle, and the axis of rotation being coupled to the feed movement of the at least one tool.

25. The processing device as claimed in claim 24, wherein the axis of rotation of the workpiece spindle lies outside the at least one optical workpiece.

26. The processing device as claimed in claim 24, wherein the workpiece spindle is provided with at least two workpiece fixtures, the axes of the workpiece fixtures being arranged on the workpiece spindle such that the axis of rotation of the workpiece spindle runs in each case outside the optical workpieces.

27. The processing device as claimed in claim 24, wherein at least two different tools are provided.

28. The processing device as claimed in claim 27, wherein at least one of the tools is provided as a preliminary turning tool and at least one tool as a precision turning tool.

29. The processing device as claimed in claim 28, wherein the preliminary turning tool is designed as a polycrystalline diamond tool, and in that the precision turning tool is designed as a monocrystalline diamond tool.

30. The processing device as claimed in claim 24, wherein tools for processing different surfaces of optical workpieces on the workpiece spindle are provided.

31. The processing device as claimed in claim 24, wherein in a processing of a curved surface of the optical workpiece, the optical workpiece is oriented in the workpiece fixture such that, in the case of a different surface curvature, the path curve segments to be covered by the at least one tool, which place lower demands on a movement travel arising from a larger radius of the curved surface, run tangentially with respect to a cutting direction of the at least one tool, and in that surface curve segments which place high demands on a movement travel arising from a smaller radius of the curved surface run radially in a direction of advance of the at least one tool.

32. The processing device as claimed in claim 24, wherein a plurality of optical workpieces are arranged radially one behind the other on the workpiece spindle.

33. The processing device as claimed in claim 24, wherein a plurality of optical workpieces are arranged in annular form on the workpiece spindle.

34. The processing device as claimed in claim 24, wherein a plurality of workpieces are arranged on the workpiece spindle at least approximately in one plane.

35. The processing device as claimed in claim 24, wherein the workpiece axis can be set obliquely with respect to the axis of rotation of the workpiece spindle in the case of steep surface curvatures of the workpieces.